"The geographic scope of these incidents strongly suggest an organised effort to denigrate the memory of the most famous of the 1.5 million Jewish children murdered by the Nazis in the World War Two Holocaust," associate dean Abraham Cooper said.

"Anne Frank is studied and revered by millions of Japanese," Mr Cooper added. "Only people imbued with bigotry and hatred would seek to destroy Anne's historic words of courage, hope and love in the face of impending doom."